Manufacture of sound-records



E. E. NOVUTNY.

MANUFACTUHE 0F SOUND RECORDS. APPLICATIQN FILED JULY 21,1920. RENEwEn MAY'3,1921.

1,398, 1 44. Patented Nov. 22, 1921.

NVENTR fifa/E /oro 21722/ im ATTORNEYS UNITED STATES PATENT OFFICE.

EMIL E. NOVOTNY, OF LOGAN, PHILADELPHIA, PENNSYLVANIA, ASSIGNOR T0 .TOHN STOGDELL STORES, OF PHILADELPHIA, PENNSYLVANIA.

MANUFACTURE OF SOUND-RECORDS.

Application led July 21, 1920, Serial No. 397,926. Renewed May 8, 1921.

This invention relates to the manufacture pf sound records or disks such as are used 1n connection with phonographs and similar sound reproducing machines.

In this industry the desirability of making a record Which, when played, will faithfully and accurately reproduce the original tones with fullness, yclearness and resonance, is Well recognized. It is further appreciated that the degree of perfection in sound reproduction is dependent, to a great extent, upon the physical characteristics of the body of the sound record itself. It ha's been found that if the body structure of a record is com'- posed of what might be termed of a relatively soft, loose, or cellular mass, which is lacking in hardness, compactness and density, there is a distinct tendency for the body of the record during the playing of the selection, to absorb the under-tones and overtones, thereby failing in full and efficient transmisslon through the stylus to the sound box. This results in faulty, dull, or subdued reproduction, particularly as to under-tones andover-tones which can be clearly heard during the singing` or playing of the original selection, but Which practically disappear when the record is played. Numerous attempts have been made to produce a sound record of the requisite hardness and density to .avoid the absorption of sound, as above pointed out, but heretofore, so far as I am aware, efforts in this direction have not been successful for the reason that when a record of sufficient hardness and density has been made it has been found to be entirely too brittle and frangible for practical purposes.

.In other words, the advantages obtained from the standpoint of hardness and density in the record have been more than offset by the fact that such a record will easily chip or break, and will undergo attrition or rapid Specification of Letters Patent.

Patented Nov. 22,1921.

Serial No. 466,534.

wearing under the action of the stylus or needle, particularly when the latter is of steel. A steel stylus or needle will rapidly break off or destroy the thin, brittle minute walls of the sound grooves of the record thus ruining the latter.,- Furthermore the exceeding brittleness of such a record renders it easily broken so that it has been heretofore practically impossible to make a record hard and dense enough to produce full and clear under-tones and over-tones, and at the :same time have it stand up under the wear and tear incident to handling and, use.

With my invention hoWever'I am enabled to produce a hard, dense, compact sound record which will clearly, faithfully and accurately reproduce original over-tones and under-tones, and which possessing strength and tenacity and lacking brittleness and frangibility is capable of withstandingi shocks and jars and the Wear anld tear occurring in service.

My invention consists in the construction, combination and arrangement of parts set forth in and falling Within the scope of the appended claims.

In the accompanying drawings:

Figure l, is a cross sectional view of a blank such as is employedin making my improved record.

Fig. 2, is a similar view of my complete record.

Before entering into a detailed description of my invention I will briefiy state that in the manufacture of my phonograph record I select a porous base or bosy which may be in` the` nature of a fibrous substance. This I impregnate, short of the point of saturation, with a cementitious materlal which is capable of subsequent reaction to assume a hard, set and preferably infusible form. For this cementitious substance I prefer to emplo a synthetic resin preferably 1n the nature o a condensation product suc as results from the reaction of a phenol and an aldehyde. The impregnated fiber base or body 1s then so operated u on that the cementitious materialis artia ly hardened and set, but not to suc an extent as to render the same capable of further compres-A sion under molding pressure. In this condition I lcoat the .impregnated base either on one or both faces with a cementitious material, such as the synthetic resin above mentioned, mixed however with a hardening substance such as barium sulfate. and pressure this coating will assume a very hard, dense and closely compacted form.

' This coating is intended to form an inner,

sound-repelling coating, for I apply ornimpose thereon an outer coating in which the grooves of the record are formed. This outer coating, which is also of a cementitious material such as the synthetic resin nientioned, is however, softer andmore tenuous than the barrier coating and of a more skinlike nature. Therefore, it is not as brittle as the barrier coating, nor as hard, and is not as susceptible to'- breakage but possesses greater tensile strength and resistance to shocks and blows. The inner sound-repelp ling coating, by reason of its hardness Iand consequent brittleness, while it would not be well adapted for the outer coating of thev record because of its liability to breakage, yet serves admirably to prevent sound absorption bythe fiber base, as it serves a barrier between the outer coating and such l base. The result is that in the playing of the record the over-tones and undertones instead of being absorbed by the body of the record, are thrown outward by this inner or barrier coating and are transmitted through the stylus to the sound box, thus causing the selection to be rendered in full, clear and resonant tones. i

Referring now to the accompanying drawings in detail, and particularly to Fig. 1

which shows a blank or disk from which the' sound record may be made, the numeral 1 indicates` the body or base which may be of any suitable material, but I prefer to have 1t composed of a porous substance, preferably of a fibrous nature such as felted paper consisting chiefly of wood fiber, although vI may utilize any open mesh material of suitable strength,'even chip board or straw board. This base 1, I preferably impregnate, but not to the point of. saturation, with a minimum amount of cementitious material.

This material is preferably in the nature of' a synthetic resin such as a condensation product produ-ced by the reaction of henol and an aldehyde. For 'this Vpurpose use such well known commercial forms of phenolic condensation products as bakelite o'r condensite, or any suitable cementitious material capable of assuming a hard and set form.- I use a minimum amount of the cementitious material for impregnation urposes in order that the cellular structure o the fiber will be capable of compressiomfunder molding pressure, without forcing any material quantity of the impregnated material from its interstices. lI prefer to subject the Under heat mayv -bath composed of cementitious material, such as a synthetic resin or condensation product above mentioned, mixed however with a suit-l able hardening material, ,such as barium sulfate, or metallic oxids, such as iron joxid or zinc oxid. If desired the mixture may also contain a suitable catalyst, such as nigrosin or zinc chlorid, the catalyst being employed for the purpose of hastening the hardening and setting of the' cementitious material. The mixture thus com osed of the synthetic resin, the barium sul ate and the catalyst may nfw be ground on a printers ink grinding mill, a good mixture being one part of barium sulfate to two parts of phenolic gum carried in a Solutio-n .of 'two parts of proper solvents such as alcohol, benzol, acetone or the like. The dipping of the impregnated body 1 into the bath will result in the coating of such body, and after the dipping the article may be placed in a suitable oven,

such as a vacuum oven, for the pu se of driving oil the solvent and of hardening and setting the coating which is indicated by the numeral 3. The 'coating 3, which is intended to form the sound-re elling coating to prevent absorption of t e sounds by the bod or base 1, during the playing of the recor is not at this time hardened and set to its nal, infusible form, but is still capableof taking'an impression under molding pressure. At such stage the thus coated article is provided with a second or exterior coating shown at 4, and which is applied by dipl ing the article in a bath composed of a synt etic resin, of varnish-like consistency' which however contains a small percentage, of a soft filler, such as lamp black, the proportion-of lamp .black employed being about twelve per vcentfby weight of the phenolic gum used in the mixture of the outer coatin The material of the outer coating contains no barium sulfate, and therefore will not assume the same extremely hard, brittle condition of the inner coating 3. This outer i coatin is now dried in the oven to drive off the so vent and to partially harden and set the coating to a non-flowing or skin-like consistency. The blank is now ready for the molding of the record, and this may be done in the usual manner by placing the blank against the grooved face of a record matrix and subjecting the same while so placed to heat and pressure in a suitable press to reproduce in the Jface or faces ot' the blank sound grooves 5 complemental to the elevations oi' the matrix, and at the same time to harden and set all of the cementitious material of the record to its final, hard, infusible form. In the complete record the. result will be that theinner or sound-repelling layers or coating 3 will be muc-h harder and denser, but far more brittle than the outer coating oi layers 4, the latter however being more tenuous, smooth and skin-like than the inner coating. This results in an ideal record, for

- the inner hard coating 3 Will prevent the absorption of sound by the body of the record during playing, while the outer coatingr being smooth and of great tensile strength will prevent the breaking or cracking .of the record under usage. At the same time the fibrous material of the base, reinforced and cemented by the impregnating material, will insure a tough and kdurable record which is practically unbreakable and which ina-y be dropped and stepped upon or otherwise subjected to violent usage without breaking..

It desired, in place of the synthetic resins or condensation products herein mentioned, I may use as the cementitious material, those shellacs mixed with suitable fillers commonly employed in this art in the making of sound records,and therefore Where I herein use the term cementitious material, I wish it to be understood as including such shellacs, or

other substances suitable for the purpose.

Furthermore-instead of first impregnating the porous or fibrous body with the cementitious material, and then subsequently as a separate operation applying the inner or sound-repelling coating thereto, I may impregnate the porous or fibrous body simultaneously wit-h the application of thisinner coating, this being done by dipping the fiber disks into a bath such as has been described for the formation of the inner coating, continuing the dipping process for a sufficient length of time to permit of the material of the bath being absorbed by the cellular mass of the fiber until the proper degree of impregnation has been reached, at the same time resulting in the deposit of a sufficient amount of. the material of the bath upon the faces of the liber body to form the coating 3.

It will, of course, be understood from the 1 above description that in the nished record,

both the inner or barrier coating and the outer or grooved face coating are in a set, non-owing condition, but the inner or barrier coating is harder and more brittle than the outer coating, While the latter is more elastic and tenuous than the inner or barrier coating. Therefore, where I have in the claims used the expression relativel soft, with reference to the outer coating, do not wish to be understood as conveying the impression that this outer coating is in any manner plastic or pliable, but I wish to be understood as meaning that this outer coating is less brittle, but more tenuous and elastic than the inner coating, as before explained.

While I have herein shown and described a preferred embodiment of my invention, I Wish it to be understood that I do not limit myself to all the precise details set forth by Way of illustration, as modification and variation may be made without departing from the spirit of the invention or exceedingxthe scope of the appended claims. hat I claim is:

l. A sound record comprising a supporting body having a grooved sound-reproducing face, and a sound-repelling barrier interposed between the grooved face and thesupporting body. f

2. A sound record comprising a body portion, a relatively hard, dense coating applied thereto and a relatively soft exterior coating imposed upon the hard, dense coating and having lsound grooves formed therein.

3. sound record comprising a body portion, a relatively hard dense cementitious coating applied to the body7 portion and a relatively soft, cementitious coating applied to the relatively hard coating and having sound grooves formed therein.

4. A sound record comprising a body portion impregnated with cementitious material and having a plurality of coatin s also of cementitious material, one of sai coatings being harder than the other, the softer coating having sound grooves formed therein.

5. A sound record comprising a fibrous body portion impregnated With a cementitious material, a relatively hard and brittle coating applied to said body portion,and a skin-like coating relatively less brittle than the first mentioned coating, applied to the latter, said skin-like coating forming an exterior face of the record and having sound grooves therein.

6. A sound record having a relatively hard cementitious coating containing barium sulfate, said sound record having a grooved face section.

7 A sound record comprising a body portion, a relatively hard cementitious coating containing barium sulfate applied to a face of the body portion, and a relatively soft coating formed of a hard and set synthetic resin imposed upon the relatively hard coating and having sound grooves therein.

8. A sound record havin a plurality of imposed coatings thereon, said coatings being composed of hard and set synthetic resinous material, each coating differing in hardness from the other, the exterior coating having sound ooves formed therein.

9. T e herein described method of making a sound record which comprises coating a body portion with a mixture of cementitious materlal and a hardening ant to produce a` relatively hard coating, t en applyin a second coating of cementitious materia to 5 the first mentioned coating to produce a relatively soft skin-like coating and then subjecting the coated body to heat and pressure against a sound record matrix to harden and set the cementitious material and to produce sound grooves in the4 face of the article.

Signed at New York city, in the county of New York and State of New York, this 14th day of July, A. D. 1920.

EMIL E. NOVOTNY. 

